The number of patients treated with antiplatelet agents increases annually. It is reported that over 20 million people in the U.S. alone take aspirin daily to induce some level of platelets inhibition. Clinical data shows that not all patients receive the full benefits of aspirin, and that a large patient to patient variability exists in aspirin induced platelet inhibition. In addition to aspirin use, a significant annual increase in the administration of intravenous GPIIbIIIa inhibitors has been occurring for the past 5 years. It is estimated that over 2.5 million patients annually are candidates for intravenous anti-platelet therapy. In angioplasty alone 35% of patients receive GPIIbIIIa therapy. To date there is not a reliable assay to detect GPIIbIIIa inhibition, and the cost of 24 hours GPIIbIIIa infusion is $320-460 for Integrilin and $1,800 for ReoPro. In addition to angioplasty, more than 1.3 million patients are discharged from hospitals annually with unstable angina, creating a market need and market potential for monitoring the extent of platelet inhibition. [unreadable] [unreadable] There is no current test on the market that can ensure that platelet function has been inhibited for patients at risk. The Medical Innovations International (MII) Cardiovascular Platelet Time Detection System is intended to be the worlds first platelet function test which provides a means and device that can determine if platelet function has been inhibited, therefore allowing the attending physician to adjust pharmacologic parameters prior to intervention. Platelet time testing has the potential to lead to reduced risk of adverse events associated with platelet initiation of coagulation, clot formation, and stroke-related embolization. [unreadable] [unreadable] Specific aims of this proposal are: A) Develop detection system capable of rapid detection of ATP in small samples of whole blood. B) To evaluate the prevalence of aspirin resistance of refractoriness in platelets of normal healthy volunteer subjects. [unreadable] [unreadable]